I just acquired a Tyan Tiger 230 S2507 for parts or repair. The board posts and boots but the problem is all 4 fan ports do not spin up the fans. I am going to guess the two 800MHz PIIIs it came with are no good. Yum, toasty. I am using two 1BGHz SL52Rs. Unfortunately, I am away, and will be a bit before I can mess with it again. The BIOS is similar to my S1834 with only a few options different. I did not see any fan control, only the monitoring. I am going to reflash the CMOS to make sure it is not a BIOS issue, especially since there is an S2507, S2507S, and S2507T. I don't see any bad caps, but I will look at it under a scope when I get a chance.
If I can't fix it, I think I will roll the dice and use a 3-pin to 4-pin Molex adapter or period-correct fan controller, to replace my Tiger 133 S1834 as my Windows 2000 Pro machine.